Technology for cooling a power reception unit and a power storage unit in a wireless power transfer system is conventionally known. As such technology, for example, a wireless power receiver, which changes a cooling capability of a cooling device according to power reception efficiency of the power reception unit is disclosed in Patent Document 1. In Patent Document 2, a wireless power transmitter which controls a temperature control means of an alternating current (AC) power supply according to an operation state of a power transmission unit is disclosed.